Bobby, Liam and Zane had some stickers in the ratio of 3 : 4 : 7. Zane gave 40% of his stickers to Bobby and Liam. As a result, Bobby had the same number of stickers as Liam and Zane had 35 fewer stickers than Bobby.

1. What was the percentage increase in Bobby's stickers after receiving from Zane?
2. How many stickers did Liam have at first?

Bobby	Liam	Zane	Total
3 u	4 u	7 u	14 u
+ 2.8 u		- 2.8 u
4.9 u	4.9 u	4.2 u	14 u

(a)
Number of stickers that Zane gave away
= 40% x 7
= ⁴⁰₁₀₀ x 7
= 2.8 u

Number of stickers that Bobby and Liam each had in the end
= (14 u - 4.2 u) ÷ 2
= 9.8 u ÷ 2
= 4.9 u

Increase in the number of stickers that Bobby had
= 4.9 u - 3 u
= 1.9 u

Percentage increase in Bobby's stickers after receiving from Zane
= ^1.9₃ x 100%
= 63.333333333333%

(b)
4.9 u = 4.2 u + 35
4.9 u - 4.2 u = 35
0.7 u = 35

1 u = 35 ÷ 0.7 = 50

Number of stickers that Liam had at first
= 4 u
= 4 x 50
= 200

Answer(s): (a) 63.333333333333%; (b) 200